These Plastic Balls Are Fixing An Unexpected Problem For California

14 Oct.,2022


According to Sky News, Los Angeles was the first city in the United States to use this technology. It deployed 400,00 of these four-inch shade balls in 2008 in the Ivanhoe Reservoir because it was the cheapest way to decrease bromate levels in the water and prevent algae growth (via UPenn). According to PBS, they could have used other, pricier covers for the water but it would have cost them $250 million more.

They repeated the process for the second time in 2015 when they dumped 96 million into a 175-acre reservoir in Los Angeles. According to National Geographic, this reservoir could hold up to 3.3 million gallons of water and had "enough to supply the entire city with enough drinking water for up to three weeks."

Not only did they want the balls to be able to stymie the growth of algae and keep contaminants out, but city officials also deployed these balls to slow down the inevitable water evaporation by up to 90% caused by drought. At the time, California was going through a historic drought. In a time, when the state needed to obtain as much water as it could get, the balls were projected to save up to 300 million gallons of water for the city, which equaled enough drinking water for roughly 8,100 people (via PBS).